A farm tractor and baler sit in a hay field on a misty morning near Cremona, Alta., Tuesday, Aug. 30, 2016. Canadian farmers are looking to more sustainable farming techniques like capturing carbon in the soil as the warnings grow louder that our food supplies are at risk from climate change and land degradation. Elections Canada says whether discussing the veracity of climate change becomes a partisan issue for third parties during the election will be decided on a case-by-case basis and only if it receives complaints. THE CANADIAN PRESS/Jeff McIntosh

Elections Canada says it will decide on a case-by-case basis whether discussing the legitimacy of climate change becomes a partisan issue for third parties during the federal campaign, and only if it receives complaints.

Environment groups say they feel muzzled from speaking out about the urgency of climate change after the federal elections agency warned earlier this summer that doing so could be considered partisan.

The Canada Elections Act could consider advertising partisan if it opposes or supports a policy positions of any party or candidate, even without naming them.

If the advertising exceeds $500, third parties would have to register with Elections Canada, raising fears among some environmental charities that the Canada Revenue Agency could also decide they are partisan and put their tax status in jeopardy.

In the case of climate change, People’s Party of Canada Leader Maxime Bernier has taken a position that climate change is not an emergency nor caused by humans, which could potentially makes any argument saying differently a partisan statement under the law.

Clean Energy Canada has already restricted some of its responses to party positions to avoid running afoul of the law, while Greenpeace Canada is planning to cease all advertising on climate change during the writ period.

An Elections Canada spokeswoman says the rules around advertising for third parties are not new, but concedes the concerns about climate change may be coming up only now because the environment is poised to play a bigger role in the campaign, which is expected to get underway early next month.